Under normal operating conditions CDMA devices, (Code Division Multiple Access)—(e.g. AMPS, IS 95, 1×CDMA, EV-DO, and so forth) can see multiple CDMA carrier signals in a given geographic region. While all such RF systems are equal in their capability to provide call processing and data service to the wireless device, that are not equal in the costs associated with the services they provide. In particular, carriers negotiate roaming agreements so that users can utilize the systems with the most favorable rates and carriers do not have the burden of building out the network in all areas. The problem of which this invention addresses, is the current inability of manufacturers and carriers to test various conditions that a mobile operator will encounter when roaming.
When a mobile or cellular telephone is moved outside of its base area, the telephone is switched from the base area system to an alternate system provider so that service can continue for the user. This is commonly referred to as Roaming. To successfully roam, CDMA devices use a Preferred Roaming List (PRL) to determine which wireless system to register. The roaming list provides information such as: System Type; Negative or Preferred System; Geo Information; Priority; Acquisition Index; Roam Indicator; System ID (SID); Network ID (NID); Association Inclusion; Association Tag; Pilot Number Association; Data Association and Subnet ID. Based on this information and the system acquisition algorithm, the CDMA device determines which system it should acquire and use for service.
In order to switch the user to an alternate system provider, the mobile telephone will access system records in the PRL stored in the memory of the mobile phone. Based on the system records stored in the PRL, the mobile phone will typically select an alternative system service provider that will be used to continue service for the user and, based on this selection and the associated information stored in the PRL system records, the mobile phone will automatically access the selected service provider on behalf of the user.
While mobile and cellular telephones have enabled the operators of the phones to roam over large geographic areas while maintaining immediate access to telephony services, the current ability to test the roaming selection is expensive, inaccurrate, and many times results in irate customers who discover a problem. Mobile stations comprising cellular telephones or wireless handsets are operable in cooperation with cellular or Personal Communications Services (PCS) communications systems. Cellular communication systems (wireless carriers) typically provide service to a geographic market area by dividing the area into many smaller areas or cells. Each cell is serviced by a radio transceiver (i.e., a transmitter-receiver base station or cell site). The cell sites or base stations may be connected to Mobile Telephone Switching Offices (MTSOs) or Mobile Switching Centers (MSCs) through landlines or other communication links, and the MTSOs may, in turn, be connected via landlines to the Public Switched Telephone Network (PSTN).
The PRL is stored in the mobile phone's non-volatile memory and, during system initialization, the entire PRL is moved and stored in the unit's RAM for later access during a System Selection and Preferred Roaming operation. Any given market area may be serviced by competing service providers of cellular air time communication services. The competing wireless carriers are assigned different groups of frequencies through which services are provided. A frequency set typically includes control channels and voice channels. The control channels are used for preliminary communications between a mobile station and a cell site for setting up a call, after which a voice channel is assigned for the mobile station's use on that call. The assigned frequency sets are generally referred to as “A band frequencies” and “B band frequencies”. Typically, the A band frequencies are reserved for non-wireline service providers, while the B band frequencies are reserved for the incumbent wireline service providers. While each frequency set for a given cellular service market area is assigned to only one service provider, in different market areas the same frequency set may be assigned to different service providers or companies.
Depending upon which wireless carrier the user of the mobile station subscribes to, the home frequency set of the user may correspond to the A frequency band or the B frequency band. Whenever a call is placed by the mobile station, the unit will ordinarily attempt to use the home frequency set to establish the call. If a call is handled outside of the user's home market area, then the unit is said to be “roaming” and service will be attempted through a frequency set of a non-home service provider. Typically, the user's home service provider will have a roaming agreement or reciprocal billing arrangement with the non-home service provider to permit service to be extended to the user's mobile unit when it is roaming in the non-home service provider's market area. Due to the imposition of surcharges, the airtime charges when the mobile station is roaming are customarily higher than when it is operating within its base network.
Operation under a roaming condition is often under the control of the mobile station user. The user can select whether the mobile station will operate in a Base System Only, A Band Only, B Band Only, A Band Preferred, or B Band Preferred operating mode. The user typically controls the system preference and mode operation through menu choice or selection. This current method of roaming control is conventionally known as “Preferred System Selection”. In the most common roaming situation, the mobile station remains on the same band as the home cellular network. That is, if the mobile station is homed to a cellular network with an odd numbered SID (which is normally assigned to an A band cellular service provider), then the mobile station will obtain service from the A band cellular service provider when roaming.
Moreover, some large companies have come to depend upon the use of mobile stations and wireless communications. As a result of the large volume of such usage, they have set up corporate accounts with wireless carriers. These accounts are referred to by the wireless carriers as National Accounts. Preferred roaming rates may be negotiated for a National Account with particular wireless carriers in certain geographic market areas. Thus, when a mobile station roams to one of these market areas, the National Account subscriber may prefer a different wireless carrier from the carrier preferred by the mass market. Furthermore, a corporation may require its personnel to subscribe to particular advanced services, e.g., a messaging service so the personnel is always reachable. Conventional mobile station equipment and systems do not permit a corporation to control which carrier roaming personnel will use in order to obtain beneficial rates and to receive selected required advanced services.
It is clear that a device's ability to acquire the proper system is paramount not only for user satisfaction, but also for the carrier to provide the most cost effective service. Thus, proper testing of system acquisition and section of the PRL order is of utmost importance. Accordingly, a need remains for testing of new phone, mobile stations and PRL.